21525530503 has 4 divisors (see below), whose sum is σ = 21784874328. Its totient is φ = 21266186680.

The previous prime is 21525530497. The next prime is 21525530603. The reversal of 21525530503 is 30503552512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21525530503 - 2¹³ = 21525522311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525530303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129671788 + ... + 129671953.

It is an arithmetic number, because the mean of its divisors is an integer number (5446218582).

Almost surely, 2^21525530503 is an apocalyptic number.

21525530503 is a deficient number, since it is larger than the sum of its proper divisors (259343825).

21525530503 is an equidigital number, since it uses as much as digits as its factorization.

21525530503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259343824.

The product of its (nonzero) digits is 22500, while the sum is 31.

The spelling of 21525530503 in words is "twenty-one billion, five hundred twenty-five million, five hundred thirty thousand, five hundred three".